Marijuana Grow Lights Interfering with Ham Radio Transmissions

Amateur radio operators across the country have recently been noticing a harsh audible buzz when switching on their equipment. The source of the interference has been traced to cheap electrical ballasts used to regulate indoor lamps that are used to grow marijuana. The cheap ballasts that are causing the problems often have fake FCC-compliance stickers, which may go unnoticed by amateur growers.

Marijuana grow lights can be powerful enough to generate the same amount of radio interference as a 1,000 watt AM radio station, and one of the cheap ballasts popular among home marijuana growers was found to produce 640 times as much interference as a legal, FCC-approved unit.

The American Radio Relay League has filed four complaints to the FCC regarding this interference, but have yet to receive a response. "My prediction is that as more and more states legalize marijuana, the number of growers is going to increase exponentially and overwhelm the FCC's ability to regulate it," said retired Coast Guard officer and ham radio enthusiast Roger Johnson.

Johnson has tried to get legislators in Maine to ban the sale of these cheap ballasts, but a committee vetoed the bill as it could pre-empt federal law.

Colorado-based amateur radio operator Tom Thompson took matters into his own hands and created a filter that almost eliminates the interference. He said that he seeks out home-growers causing interference so he can “give them a filter and give them instructions how to install it. Some won't cooperate, but most do.”